In describing the failure of Christian schools and the activities of violent gangs at my college, something constantly shows up: the people who failed didn't understand what was wrong.
One Christian did an analysis of people who started new churches and failed, and he concluded: they usually didn't understand why they failed. When I talk to unsuccessful missionaries here in Mexico, I usually see that they don't understand what they're doing wrong.
Furthermore, when you try to tell them what they're doing wrong, they reject your explanation, because it is so different from what they believe. It takes wisdom (along with humility) to acknowledge that your failure is based on something you deeply believe but is still false.